Two-way rotary joint for fluids

ABSTRACT

A two-way rotary joint for fluids is disclosed. An illustrative example of the rotary joint includes a main body provided with two inlet ports, and a rotor rotatably coupled to the main body. The rotor has two passages each in communication with a respective one of the inlet ports in the main body. A ring-shaped hub is rotatably supported relative to the rotor and has a radial outlet port in communication with one of the passages in the rotor.

TECHNICAL FIELD

The present invention refers to a rotary joint for fluids, that is adevice used to transmit a pressurized fluid from a fixed part to arotating one while preventing spilling of the fluid through proper sealsor gaskets.

BACKGROUND ART

A rotary joint generally comprises a fixed part named stator or body,and a rotary or rotatable part named rotor. Such rotary joint may beprovided either with only one passage (or way), or with two or morepassages independent from each other, according to the requiredapplications in a plant.

The known rotary joints are of the type comprising two independentpassages each comprising one (axial or radial) inlet port provided inthe stator. One of the passages is provided with an axial outlet portand the other passage is provided with a radial outlet port, with bothoutlet ports being located in the rotor. Joints of this type aregenerally fitted to the bottom of oleodynamic or pneumatic cylinders oftake-up reels of metal sheets.

The two passages or ways are used to drive the cylinder, i.e. one way isused for the rod extension and the other for retracting the rod,respectively.

Two examples of rotary joints of this type, with an axial outlet port 21and a radial outlet port 22, are described in the partiallycross-sectioned side views of FIGS. 3 and 4. The body 10 of the jointincludes two inlets 11 and 12, connected to the outlets 21 and 22respectively, with the body being further secured to the cylinder (notshown in the Figures) by means of a mounting on the cylinder bottom.

The known devices of this type show an inconvenience due to fact thatthe joint rotor has to be threaded for being connected to the cylinderbottom, and therefore it is not always possible to obtain a desiredangular arrangement, after the parts have been tightened together. Thisinconvenience is particularly felt in the joint maintenance operations,for example when replacement of the joint is needed.

DISCLOSURE OF THE INVENTION

It is an an object of present invention to overcome the above mentioneddrawback, and particularly to provide a two-way rotary joint having aradial outlet port that allows a positioning thereof according to anygiven or desired direction.

According to the invention, this object is accomplished by means of arotary joint provided with a rotor having a radial outlet port that isangularly orientable independently from the axial outlet port of therotor.

Further advantageous characteristics will become apparent upon study ofthe Detailed Description of Preferred Embodiments and the appendeddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be disclosed with reference to the attacheddrawings illustrating preferred non-limiting embodiments thereof, inwhich:

FIGS. 1 and 2 are partially cross-sectioned side views illustrating twoembodiments of a rotary joint capable of being oriented along a givendirection according to the present invention;

FIGS. 3 and 4, already described, illustrate two-way rotary jointsaccording to the prior art; and

FIGS. 5 and 6 show some details of two embodiments of the sealingsystem.

Throughout all the Figures the same numeral references have been used toindicate the same or equivalent parts.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to FIG. 1, a rotary joint according to the inventioncomprises a body 10 and a rotor 3 provided with a threaded end portion13 and hexagonal planes for locking it to the cylinder bottom.

In the Figures, both inlet openings 1 and 2 in body or stator 10 areradial, however they could also be axially extending ports.

A hub 9, housed in a ring-shaped seat, is rotatably fitted to rotor 3,around the part far from the threaded portion. A spacer 4, insertedbetween the hub and the body 10 of the joint prevents the hub axialdisplacement.

Two axial passages or ducts 11 and 12 are formed in the rotor for thefluid passage, and one of them (passage 11 in FIG. 1) is closed by anend plug 6 and connected through a radial hole 7 to a ring-shapedchannel 8 that in turn is provided with a radial outlet port 22 formedin the hub 9.

In rotor 3 two ring-shaped grooves are provided sideways to the channel8 which make up seats for as many sealing gaskets 5 having a circularcross-section (e.g. O rings). These gaskets prevent fluid from spillingoutside and allow to angularly orient the hub 9—and therefore the radialoutlet 22—along 4 outlet 22 of the rotary joint according to theinvention can be oriented in the desired angular direction.

According to another embodiment (schematically shown in FIG. 5), thechannels for receiving the sealing gaskets 5 can be formed in the hub 9.

FIG. 2 shows another embodiment of an orientable joint according to theinvention, in which only one axial duct 21 is provided in the rotor,particularly with its axis coincident with that of the rotor, and anannular chamber 14 is provided communicating with the channel 8 which inturn opens on the outlet 22. Although not shown in the drawings, alsothe other outlet port (11 or 21, depending on which Figure) can be aradial outlet, that can be oriented in an independent manner from theother outlet port.

In the embodiment of the seal system shown in the detail view of FIG. 5,it is also provided that the orientable hub 9 housing the gaskets 5 ismounted at the end of the threaded portion 13.

According to the embodiment shown in FIG. 6, the orientable hub 19 isfitted at the end of the threaded portion 13, while the gaskets 15 areof a flat type, and located between shoulders 16, 17.

Although the invention has been described with reference to preferredembodiments, it is generally susceptible of other applications andchanges that fall within the scope of the invention, as will becomeevident to the skilled in the art.

INDUSTRIAL APPLICABILITY

The invention is applicable to a rotary joint for fluids used totransmit a pressurized fluid in machinery such as, for example, take-upreels of metal sheets.

What is claimed is:
 1. A rotary joint for fluids comprising: a main bodyprovided with a first inlet port and a second inlet port; a rotorrotatably coupled to said main body and provided with two passagescommunicating with said first and second inlet ports, respectively, saidrotor having at least one outlet port communicating with a first one ofsaid two passages; and a hub having a radial outlet port, said hub beingrotatably supported around said rotor with said radial outlet port incommunication with a second one of said two passages, whereby saidradial outlet port is angularly orientable independently from said atleast one outlet port of said rotor.
 2. The rotary joint for fluidsaccording to claim 1, wherein said at least one outlet port of saidrotor is an axial outlet port.
 3. A rotary joint for fluids comprising:a main body provided with a first inlet port and a second inlet port; arotor rotatably coupled to said main body and provided with at least oneoutlet port communicating with a respective one of said first and secondinlet ports; and a hub fitted to said rotor through sealing means, saidhub and said rotor forming an assembly having an annular channel formedbetween said hub and said rotor, said hub being provided with an outletport communicating with said annular channel, said annular channelfurther communicating, through a radial hole in said rotor, with arespective one of said first and second inlet ports.
 4. The rotary jointfor fluids according to claim 3, wherein said hub is ring-shaped.
 5. Therotary joint for fluids according to claim 3, wherein said rotor isprovided with two axial ducts, one of which communicates with saidannular channel, while the other is closed by a plug.
 6. The rotaryjoint for fluids according to claim 3, wherein said rotor is providedwith an axial duct and an annular chamber that is in communication withsaid annular channel.
 7. The rotary joint for fluids according to claim3, wherein said rotor is provided with a threaded portion, said hub ismounted intermediate said threaded portion and said main body, and aspacer is inserted between said hub and said main body to prevent anyaxial displacement of said hub.
 8. The rotary joint for fluids accordingto claim 3, wherein said sealing means includes gaskets having circularcross-sections and located in seats formed between said hub and saidrotor.
 9. The rotary joint for fluids according to claim 3, wherein saidsealing means includes gaskets having flat cross-sections.
 10. Therotary joint for fluids according to claim 3, wherein said at least oneoutlet port of said rotor is an axial outlet port.
 11. The rotary jointfor fluids according to claim 3, wherein said outlet port of said hub isa radial outlet port.
 12. A rotary joint for fluids comprising: a mainbody provided with a first inlet port and a second inlet port; a rotorrotatably coupled to said main body and provided with at least oneoutlet port communicating with a respective one of said first and secondinlet ports; and a hub fitted to said rotor through sealing means, saidhub being provided with an annular channel and with a radial outlet portcommunicating with said annular channel, said annular channel furthercommunicating, through a radial hole in said rotor, with a respectiveone of said first and second inlet ports.
 13. The rotary joint forfluids according to claim 12, wherein said hub is ring-shaped.
 14. Therotary joint for fluids according to claim 12, wherein said rotor isprovided with two axial ducts, one of which communicates with saidannular channel, while the other is closed by a plug.
 15. The rotaryjoint for fluids according to claim 12, wherein said rotor is providedwith an axial duct and an annular chamber that is in communication withsaid annular channel.
 16. The rotary joint for fluids according to claim12, wherein said rotor is provided with a threaded portion, said hub ismounted intermediate said threaded portion and said main body, and aspacer is inserted between said hub and said main body to prevent anyaxial displacement of said hub.
 17. The rotary joint for fluidsaccording to claim 12, wherein said sealing means includes gasketshaving circular cross-sections and located in seats formed between saidhub and said rotor.
 18. The rotary joint for fluids according to claim12, wherein said sealing means includes gaskets having flatcross-sections.
 19. The rotary joint for fluids according to claim 12,wherein said at least one outlet port of said rotor is an axial outletport.